[UNOFFICIAL/FANMADE] 0.17 Discussion Thread 2

[Nibb31]

It would be easier to use bouyancy to escape the lower layers of a dense atmosphere. I think a rocket launched from a balloon would work much better in that kind of environment than wings.

[colonel0sanders]

Ye, assuming that Eve got the same density as kerbin it will have a radius that's 1.7 times larger than Kerbin (if it's surface acceleration is 1.7g), aka 1020 km. The difference would be something like this:

Not exactly...

If Eve is 1.7 times bigger (has 1.7 times the volume) than Kerbin, and their density is the same (thus Eve would have 1.7 times the mass), then the radius of Eve would only be about 716.1 km, compared to Kerbin's 600km. Since, for a sphere, v=(4/3)*pi*r^3, then 1.7 times the volume means (1.7)^(1/3) = 1.1935 times the radius.

EDIT: I'm not sure about surface gravity (apparently, re-reading, they've said Eve has 1.7 times the surface gravity, not mass...)

Edited August 23, 2012 by colonel0sanders

[Serratus]

It would be easier to use bouyancy to escape the lower layers of a dense atmosphere. I think a rocket launched from a balloon would work much better in that kind of environment than wings.

You are probably right. It would have to be one hell of a balloon, to lift a whole rocket... Remember that to return from Eva, we will need to deliver a WHOLE rocket to it first. And then start the whole take off sequence just like on Kerbin. Only 70% harder

[kodemunkey]

Is it hoping too much that they make VTOL a bit easier to get to grips with, as well as generally flying planes?

[BurningSky93]

Not exactly...

If Eve is 1.7 times bigger (has 1.7 times the volume) than Kerbin, and their density is the same (thus Eve would have 1.7 times the mass), then the radius of Eve would only be about 716.1 km, compared to Kerbin's 600km. Since, for a sphere, v=(4/3)*pi*r^3, then 1.7 times the volume means (1.7)^(1/3) = 1.1935 times the radius.

Actually, when assuming the desnities are equal, he's correct. See my post above.

g = ((4 pi)/3)*G*rho*r

Say g(k) is Kerbin's surface gravity, and g(e) is Eve's surface gravity, which is also equal to 1.7g(k) (which is a known value specified by Nova)

All the values in the above equation are constants in this case (as Banbite assumed density, rho, for Eve as being the same as Kerbin) except for g and r

For g(e) to equal 1.7g(k) then the radius of Eve, r(e) must be 1.7 times the radius of Kerbin r(k)

g(e) = 1.7g(k) therefore r(e)=1.7r(k) as expressed by Banbite.

Unless I've messed up severely with my physics anywhere, in which case do please correct me.

Edited August 23, 2012 by BurningSky93

[nhnifong]

I think it will be important for the parachute to open at a variable altitude based on things like velocity and air density. Because right now I think it's triggered on altitude and that won't be any fun trying to parachute my Galileo probe into the new gas giant!

[colonel0sanders]

Actually, he's correct. See my post above.

g = ((4 pi)/3)*G*rho*r

Say g(k) is Kerbin's surface gravity, and g(e) is Eve's surface gravity, which is also equal to 1.7g(k) (which is a known value specified by Nova)

All the values in the above equation are constants in this case (as Banbite assumed density, rho, for Eve as being the same as Kerbin) except for g and r

For g(e) to equal 1.7g(k) then the radius of Eve, r(e) must be 1.7 times the radius of Kerbin r(k)

g(e) = 1.7g(k) therefore r(e)=1.7r(k) as expressed by Banbite.

Unless I've messed up severely with my physics anywhere, in which case do please correct me.

Well heck - that's what I get for not reading back to the original statement. Nevermind all that then

[BurningSky93]

Well heck - that's what I get for not reading back to the original statement. Nevermind all that then

Physics and maths are wonderful things

So as stated that Eve has 1.7 times the surface gravity and a radius 100km greater than Kerbin (700km), lets see how much denser Eve is than something that is already more dense than any material known to man, shall we?

g = ((4 pi)/3)*G*rho*r, rearrange to find rho: rho = g/((4pi/3)*G*r)

Gonna do this with proportionality, because I like doing it that way.

g(e) = 1.7 g(k), r(e)=1.167r(k)

rho(e)=(1.7/1.167)rho(k) I believe?

Eve is 1.457 times as dense as Kerbin

Edited August 23, 2012 by BurningSky93

[claypool1]

Someone quoted Nova saying Eve had a radius of 700km a few pages back.

[Winter Man]

So basically, it has both 1.7 times the surface gravity and a 100km larger radius. We've successfully proven what we were already told

[colonel0sanders]

So...Eve is 1.457 times denser than Kerbin?

[BurningSky93]

So...Eve is 1.457 times denser than Kerbin?

Hivemind!

Literally just edited my post to include the calculations, refesh the page to see we had reached the same conclusion!

[colonel0sanders]

Hivemind!

Literally just edited my post to include the calculations, refesh the page to see we had reached the same conclusion!

Nice! I teach math for a living, it's the physics I'm none too familiar with

[dsmaster7173]

what if its an effect if you dont have some sattelite of sorts on the ship and you move far away from kerbin

https://dl.dropbox.com/u/575558/KSP/brokenphoto.jpg

[Randox]

Just thinking about the high gravity and super dense atmosphere on eve, and the concept of leaving.

Is anyone else imagining parking your ship in a geostationary orbit, and sending your lander down with a cable running between nose and main ship? I know there are some serious limitations with drawing ropes (though perhaps being under constant tension could sidestep that), and this is hardly a practical idea at the best of times, but I think it would be a very neat way to deal with the problem. By reeling in the ship at a low constant speed, the orbiter will only have to deal with the initial acceleration, which shouldn't pull it out of orbit (and once the lander takes off, it doesn't matter if the winch starts to drift). By going at a fairly slow speed, there will be minimal drag transmitting force back to the orbiter, so you should hopefully get back before the orbit totally destabilizes. And honestly, if you get up high enough you could cut the cable and use engines, though winching the entire way would go a long way to saving all the fuel you can for escaping that king of gravity. Also, since you want such a lander to be as light as possible, and the orbital stage to be as heavy as possible (the bigger it is relative to the lander, the less it will be affected by the initial acceleration and drag forces), it would make sense to have it tow you back out of orbit, at least as far as it can, and only then let it go (or have it self destruct because Kerbal).

In more practical terms, I think if we ever want to leave, our landers will have to be totally viable space planes, and they are going to need more efficient engines (or a fuel with a much higher energy content) than we have now if it will ever attain orbit again. And if these parts aren't provided, you can always modify an engine, make it more efficient and say it pulls some of its fuel out of Eve's atmosphere.

Edited August 24, 2012 by Randox

[TheDarkStar]

We need an atmospheric engine that needs a lot of air (enough that it has trouble at Kerbin's surface) but is very strong to get a return stage off Eve (landing is done by parachute) with an ion engine for space.

[bsalis]

Those numbers on Eve look ... heavy. Anyone like to take a guess of the Delta-V to get to Low Eve Orbit (LEO)?

Looks like my hopes of being able to get to all of the hard-surface planets and returning to Kerbin is slowly receding into the distance.

[Rickenbacker]

This is true, but it depends on the aerofoil. The high speed jets and aerobatic planes rely more on the angle pushing the air out of the way, but slower planes rely on it quite a bit due to the lower thrust-to-weight ratio and their much lower stall angle.

Well, we can argue the details, but I think we agree that the things that makes airplanes fly is that they move air equal to or greater than their own mass downwards, whether by using the pressure differentials or simply deflecting it downwards. Even if they Bernoulli principle is responsible for the lift, SOMETHING has to move down for the plane to move up (or just STAY up), you can't just claim magical pressure differences sucking the plane into the sky .

And KSP doesn't seem to do this, wings just work like reactionless rockets, as far as I can tell, adding a fixed 'up' force per wing section. Which doesn't make it easier to build space planes .

[Nibb31]

Is anyone else imagining parking your ship in a geostationary orbit, and sending your lander down with a cable running between nose and main ship? I know there are some serious limitations with drawing ropes (though perhaps being under constant tension could sidestep that), and this is hardly a practical idea at the best of times, but I think it would be a very neat way to deal with the problem. By reeling in the ship at a low constant speed, the orbiter will only have to deal with the initial acceleration, which shouldn't pull it out of orbit (and once the lander takes off, it doesn't matter if the winch starts to drift). By going at a fairly slow speed, there will be minimal drag transmitting force back to the orbiter, so you should hopefully get back before the orbit totally destabilizes.

What you have just described are the basics of the Space Elevator concept: http://en.wikipedia.org/wiki/Space_elevator

The difficulty is carrying the mass of rope (or carbon nanotube tether) necessary to reel down thousands of kilometers (whatever geostationary altitude is for a planet 1.7x the gravity of Kerbin) to the surface.

[Rickenbacker]

Is it hoping too much that they make VTOL a bit easier to get to grips with, as well as generally flying planes?

No, there will be refinements in .17, such as markers for CoG and other important points in the spaceplane hangar, so building them should be easier. Not sure about flying, the flight model is very rudimentary still. I'm at least hoping for those right-click options, so we can select which surfaces are rudders, ailerons, elevons etc, and not have the rudder flop around when rolling as it currently does .

[Winter Man]

Well, we can argue the details, but I think we agree that the things that makes airplanes fly is that they move air equal to or greater than their own mass downwards, whether by using the pressure differentials or simply deflecting it downwards. Even if they Bernoulli principle is responsible for the lift, SOMETHING has to move down for the plane to move up (or just STAY up), you can't just claim magical pressure differences sucking the plane into the sky .

And KSP doesn't seem to do this, wings just work like reactionless rockets, as far as I can tell, adding a fixed 'up' force per wing section. Which doesn't make it easier to build space planes .

Well, something doesn't have to move down to keep the plane in the air, just to climb. The force generated by the Bernoulli principle is really quite high, about enough to keep the plane in the air in level flight. The climb is performed by the angle. But you're right, KSP doesn't do anything like that, but it should

[Letum]

Well, something doesn't have to move down to keep the plane in the air, just to climb. The force generated by the Bernoulli principle is really quite high, about enough to keep the plane in the air in level flight. The climb is performed by the angle. But you're right, KSP doesn't do anything like that, but it should

Even the Bernoulli principle ultimately produces it's lift by moving air down. Specifically, it's moving the air that would have been in the low pressure zone, down below the wing.

If something goes up, then something else must go down. There are no exceptions to this.

[royalkingofgames]

space elevator.

Idea we put a rocket in a geostationary orbit around eve,then lower the lander down on a rope till it hits the surface,then pull the lander up again.

the physicists will probably say that as you lower the craft its orbit will change pulling the ship out of geostationary orbit.

if this is the case before you detach the lander it would release a rope(not attached to anything) then land the vehicle,the return stage would then rendezvous with the rope and hoist the lander up.

This may be wrong but dont be to harsh im only 12.

[Shadownailshot]

Just thinking about the high gravity and super dense atmosphere on eve, and the concept of leaving.

Is anyone else imagining parking your ship in a geostationary orbit, and sending your lander down with a cable running between nose and main ship? I know there are some serious limitations with drawing ropes (though perhaps being under constant tension could sidestep that), and this is hardly a practical idea at the best of times, but I think it would be a very neat way to deal with the problem. By reeling in the ship at a low constant speed, the orbiter will only have to deal with the initial acceleration, which shouldn't pull it out of orbit (and once the lander takes off, it doesn't matter if the winch starts to drift). By going at a fairly slow speed, there will be minimal drag transmitting force back to the orbiter, so you should hopefully get back before the orbit totally destabilizes. And honestly, if you get up high enough you could cut the cable and use engines, though winching the entire way would go a long way to saving all the fuel you can for escaping that king of gravity. Also, since you want such a lander to be as light as possible, and the orbital stage to be as heavy as possible (the bigger it is relative to the lander, the less it will be affected by the initial acceleration and drag forces), it would make sense to have it tow you back out of orbit, at least as far as it can, and only then let it go (or have it self destruct because Kerbal).

In more practical terms, I think if we ever want to leave, our landers will have to be totally viable space planes, and they are going to need more efficient engines (or a fuel with a much higher energy content) than we have now if it will ever attain orbit again. And if these parts aren't provided, you can always modify an engine, make it more efficient and say it pulls some of its fuel out of Eve's atmosphere.

So... an Interplanetary Space Elevator (ISE)? The Orbiter for the craft would have to be unGODLY massive to counterweight the lowering and raising of the lander stage. It would also be better to have docking, and just use a craft like the shuttle from Avatar. Go down on a glide with wings, and come up powered. The atmosphere on Eve is so thick, you could quite likely have a rather easy glide-to-landing. Coming up would require more thrust and fuel, but once you got out into space, you could just rendezvous with the orbiter. (OH NO I SAID THE D-WORD) I know docking isn't coming in 0.17, I'm just pitching a hypothetical scenario.

[Shadownailshot]

space elevator.

Idea we put a rocket in a geostationary orbit around eve,then lower the lander down on a rope till it hits the surface,then pull the lander up again.

the physicists will probably say that as you lower the craft its orbit will change pulling the ship out of geostationary orbit.

if this is the case before you detach the lander it would release a rope(not attached to anything) then land the vehicle,the return stage would then rendezvous with the rope and hoist the lander up.

This may be wrong but dont be to harsh im only 12.

I don't know the exact math behind it, but if the orbital craft (the actual piece with the winch) is heavy enough in relation to the lander and in a synchronous orbit, it should hold there quite fine, as long as ascent and descent are slow and steady, and you drop location is equatorial. There's no wind or anything in space (unless you count solar wind, it wont really push the craft unless it's made of special materials) so dropping the lander wouldn't pull the orbiter in odd directions. The wind on the planet (assuming it's not moving a super-sonic speeds) shouldn't be to much of an issue either.